Telephone-receiver.



No; 728,342. E PATENTED MAE 19,1903.;-

G. EfwHEELEE.

TELEPHONE RECEIVER.

APPLIOATION FILED JUNE 19, 1902.

no MODEL.

TH: Nonms PETER; w. PHGTULIYHO.. WASHINGTON4 n, c.

UNITED STATES Patented May 19, 190s.

V'PATENT QEEICE.

GEORGE E. WHEELER, OE RURL1NGTON,.1OWA,AssiGNOR rro MODERN ELEOTRIOOO., OE BURLINGTON, IOWA.

TEL-EPH o N Ej-'R Eo EIV'ER.

SPECIFICATION forming' part of Letters Patent No'. 728,342, dated May 19, 1903.

` Application nieuwe 19.1902. senti No. 112,340. (No model To all whom it may concern.-

Beit known that'I, GEORGE WHEELER, a citizen of the United States, residing at Burlington, inthe county of Des Moines and State of Iowa, have invented certain new and vu se-- ful Improvements in Telephone-Receivers; and I do declare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in telephone-receivers, and has for its object to provide a receiver which shall be simple of construction, durable and efficient in use, and comparativelyinexpensive Ofproduction, and which provides for a nicety of adjustment ofthe parts, is free from the detrimental influences caused by undue expansion and contraction, and -embodies certain features rendering it advantageous in use and in the assemblage and disassemblage of the parts.

`With these and other objects in View the invention consists of certain novel features of construction, combination, and arrangement'of parts, which will be hereinafter more fully described, and particularlypointed out in the appended claims.

one of the pole-pieces.

In the accompanying-drawings, Figurel is a vertical longitudinal section of a telephonereceiver embodying my invention. Fig. 2 is a side elevation of the magnet and block detached. Fig. 3 is a longitudinal section through the magnet and block ou a plane at right an-v gles to thatshown in Fig. l, the magnet being omitted. Fig. 4 is an enlarged detail section showing the cup, coils, pole-pieces, and diaphragm. Fig. 5 is an end view'of the'pol'epieces. Fig. 6 is a View showing the construction of the coils. Fig. 7 is a view similar to Fig. 5, showing a modification in the form of the end pieces; and Fig. 8 is a detail view of Referring now more particularly :gto the drawings, the numeral l represents the transmitter-casing, which is made of hard rubber or other suitable non-conducting material, and 2 is the cap therefor, which screws onto the casing in the usual way. Located in the casing is a metallic cup 3, which is provided with a anged seat, depression, or recess for the diaphragm 4, which is held in position therein by the cap 2. The cup 3 has a reduced tubular` extension 5, into which pro'- ject the free ends of the arms of a permanent L magnet V6. Between these arms ,is inserted a non-conducting block 7, and passing through the tubular extension and arms are screws 8, which enter 'the block and ydetachably connect the parts together. The magnet-arms are suitably'stepped or recessed to receive thepole-pieces 9, which are in the form of flat plates provided at their inner ends with longitudinalslots l0 for the passage of the screws 8, which secure said pole-pieces to the arms ofthe magnet. `As shown, -these slots open through the said inner ends of the polepieces, whereby the latter are adjustably connected tothe magnet and may be independently removed therefrom upon slacking the screws without entirely detaching said screws' or disturbing the relation of the other parts. The Outer ends of the pole-pieces are inthe form of reduced shanks or stems, which are inwardly' curved, as at 11, thus bringing them in close proximity at their extremities, and are T-shaped, the cross-pieces thereof -preferably being in the form of segmental tips 12, which coact inthe usual manner with the diaphragm 4. By thusy curving the ends of the pole-pieces so as to bring the tips in close proximity and vmaking them of T shape with tips of segmental form the magnetic lines of force, are concentrated and brought to act upon the center of thefdiaphragm, thereby rendering the latter responsive in the highest degree to the slightest variations of current strength. As the cup 3 is not connected with the casing l, but ysimply fits snugly therein, and as the screws 8 detachably connectthe cup, magnet, block, and 4pole-pieces, it will be observed that these parts are insertible and removable together andlmay be quickly and conveniently assembled and disassembled, thusA facilitating repairs and rendering the operation of assembling the parts easy and speedy. Also by the described means of fastening the pole-pieces the latter may be adjusted as desired and also removed without the necessity of detachin g any. of the correlated parts. The' tips may be so curved as to approximate an ellipse, as shown at l2 in Fig. 5, or of such shape as to form a nearly true circle, as shown in Fig. 7.

The diaphragm 4i `is preferably reinforced at its edge on both sides by stiffening-rings 12', which increase its sensitiveness and make it more active. By employing rings on both sides of the diaphragm either side of the latter may be placed outermost and the same result secured.

The coils 13 of the magnet are mounted upon the spools 14, fitted on the shanks or stems of the pole-pieces, each spool comprising a lnetallic tube or core 15, carrying non-conducting heads 16. The cores of the two spools are mechanically and electrically connected by a metallic plate 17, which is soldered or otherwise iixed to the tubes and supports the two spools in proper relation. The spools are wound right and left in series, and by the construction described I am enabled to solder or otherwise fasten the inner end of each wire, as shown at 1S, to the core, so that only the outer end requires handling. It is found in practice that the inner ends of the windings are frequently broken off by careless handling, and when such occurs more or less trouble or difficulty is experienced in making repairs. By my construction this objection is avoided, as when the outer end of the wire is broken a turn or two of the wire off the spool gives a new end to connect up again. As shown, the plate 17 contacts with the magnet and completes the circuit through the parts. The outer ends of the coils of the magnets are connected to metallic stems 19, applied on opposite sides of the block at right angles to the permanent magnet, each of said stems having a non-conducting covering 20 beyond the magnet and being provided at its inner end with an eye 20. The ends of the conducting-cords 2l have also eyes 22, which the eyes 20' overlap, and passing through these eyes are screws 23, which secure the stems and wires to the block 7, whereby said cords may be easily attached and detached, as will be readily understood.

From the foregoing description, taken in connection with the accompanying drawings, the construction, mode of operation, and advantages of the invention will be readily understood without requiring an extended eX- planation, and it will be seen that the method of supporting the magnet reduces to a minimum liability of derangement by unequal expansion and contraction, also that the construction ofthe parts renders adjustment convenient wherever required and facilitates assemblage and disassemblage, while at the sametimegiving material advantagesin point of simplicity and efficiency.

Various changes in the form, proportion,

and details of construction may be made within the scope of the invention without departing from the spirit or sacrificing any of the advantages thereof.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In a magnetic telephone, the combination of a casing, a cup fitted therein, a permanent magnet having its arms seated in the cup, a non-conducting block between the arms of the magnet, pole-pieces provided with slots opening therethrough at one end, and screws passing through the cup, slots in the polepieces and arms of the magnet and entering the block, whereby the parts are united and the pole-pieces made adjustable and detachable without the necessity ot' disconnecting the other parts, substantially as set forth.

2. In a magnetic telephone, the combination with a casing, a permanent magnet, a diaphragm and coils, of pole-pieces connected to the magnet and supporting the coils, said pole-pieces having their tips deflected inwardly beyond the coils so as to lie in close relation, and provided with T-heads, substantially as set forth.

3. In a magnetic telephone, the combination of a casing, a cup fitted therein, a permanent magnet having its arms seated in the cup, a non-conducting block between the arms of the magnet, pole-pieces provided with slots opening therethrough at one end, screws passing through the cap, slots in the pole-pieces and arms of the magnet and entering the block, whereby the parts are united and the pole-pieces iliade adjustable and detachable without the necessity of disconnecting the other parts, and coils supported by the polepieces, the latter having their tips deflected inwardly beyond the coils so as to liein close relation, substantially as set forth.

4. In a magnetic telephone, coils comprisingspools each havinga metal core and adapted to com plete the circuit when the parts are connected up, a metallic support connecting the cores, and windings upon the spools each having its outer end exposed for connection with a conductor and its inner end connected to the core, substantially as set forth.

5. In a magnetic telephone, pole-pieces having ends offset toward each other and terminating in T-pieces having segmental cross portions or tips, substantially as set forth.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

GEORGE E. WHEELER.

lVitnesses:

J. B. Woonsinn, JAMES FITZGERALD.

IIO 

